1. Technical Field of the Invention
The present invention relates generally to a container and closure for use in a hot fill or retort process. More particularly, the invention relates to a container neck and closure which promote drainage of hot fill or hot or cold bath water introduced therein during the process.
2. Description of the Related Art
In recent years, packaged products which are room temperature storage stable yet ready-to-use upon opening, i.e. they require no cooking or heating before use, have become extremely popular with the consumer. For many food products, this trend requires only minor packaging changes, such as modifying the package size to be consistent with the anticipated consumer use pattern. However, for products prone to bacterial contamination and spoilage, such as some beverages, soups, and many other food products, this trend presents some major packaging challenges.
For example, certain products need to be sterilized to reduce the initial viable bacterial concentration in a product, thereby reducing the rate at which the product will spoil and lengthening the product's shelf life. One procedure for reducing the viable bacterial concentration is sterilization by hot fill and another by retort processing. In the retort process, a chilled or ambient temperature product is poured into a container and the container is sealed. The container may be sealed by melding two sections of the container material together, such as by heat-sealing a seam on a pouch, or the container may be sealed by bonding a seal to the lip of the container, such as by induction or conduction sealing a foil-lined seal to a barrier polymer material bottle neck. The filled package is then sterilized at high temperature in a high pressure water bath. In a typical commercial production rate retort process, the package is heated from an ambient temperature of about 75° F. to a sterilizing temperature in the range of from about 212° F. to about 270° F.
During this process, retort bath water may be trapped or adhere between the threads of the container and closure making the product aesthetically unacceptable and unpleasant for use by the consumer as well as increasing the probability of bacterial growth within the threaded areas.
In a hot fill situation, the product is heated to between about 150-210 degrees Fahrenheit to kill a majority of the bacteria and then put into the container and a cap is applied. The high temperature product likewise kills the bacteria on the inside of the container and closure or closure seal. Soon after filling, to reduce the likelihood of distortion to the package and facilitate further handling and operations such as labeling and cartoning, the package is cooled. In some cases the package is simply sprayed with cool water but in some cases, where a more complete cooling is desired, the filled and capped package is submerged in cool water.
In a case where a peelable, tabbed or oversize innerseal liner is used, the small crevices around the tabs or overhead exacerbate the problem of retained water. And, should a shrink sleeve be desirable to be applied over the cap and neck for tamper-indication, this further may tend to inhibit drainage or drying and allow time for bacteria or mold to grow in the wetted areas.
In view of the deficiencies in known closures and container necks associated with hot fill and retort processes, it is apparent that a container neck and closure is needed which promotes drainage of cooling water introduced therein during a retort or hot fill process.